A highly porous solvent free PVDF/expanded graphite foam for oil/water separation

The environmental impact caused by natural and industrial water containing oils and hydrocarbons or solvents is nowadays of great concern, highlighting the need to improve the cost-efficiency and sustainability of already existing materials, or to develop new-ones with better potential. Here, we present the fabrication of a highly porous foam composed of poly(vinylidene fluoride) (PVDF) and expanded graphite (EGr) following a solvent- and template-free process. The obtained PVDF:EGr foam has a porosity of c.a. 90%, and is highly selective towards oily contaminants. The mean oil absorption capacity of PVDF:EGr foam is 12 g/g. This performance is preserved even under corrosive conditions and for various absorption-desorption cycles, demonstrating the effectiveness of the developed system for different types of wastewaters. Therefore, the developed PVDF:EGr reusable foams are promising candidates for the treatment of different types of contaminated waters, while their template and solvent-free fabrication method is ideal for a large-scale foams production.